A PCM is chosen first by its melting temperature, which should sit just above the delivery temperature the user needs, and then by latent heat, density, conductivity, stability, safety and price.
PCMs are used in macro-capsules, tube-and-shell modules, slurries or composite boards. Graphite and metal fins compensate for low conductivity.
Key facts
- Paraffins
- ≈ 5–120 °C · ≈ 150–250 kJ/kg
- Salt hydrates
- ≈ 10–120 °C · high density
- Nitrates / eutectics
- ≈ 120–350 °C
- Metallic
- ≈ 300–800 °C · high conductivity
PCM families6
- Organic phase-change materials
- Paraffin-based materials
- Salt hydrates
- Eutectic mixtures
- Metallic and high-temperature PCMs
- Encapsulated PCM modules
Selection criteria7
- Melting point vs delivery temperature
- Latent heat per kg and per m³
- Thermal conductivity
- Cycling and chemical stability
- Supercooling and segregation
- Flammability and toxicity
- Cost and availability
Formats5
- Encapsulated spheres and slabs
- Shell-and-tube PCM exchangers
- PCM in containers / thermal boxes
- Composite PCM-graphite
- PCM slurries for cooling
Related calculators
Calculators are available to staff / admin only.
Related topics
- Latent HeatPhase-change materials absorb and release heat as they melt and freeze — compact storage at a nearly constant temperature.
- District CoolingChilled-water, ice and PCM storage shift cooling load to off-peak hours and shrink chiller plants.
- Thermal BatteryIntegrated systems that turn electricity — often cheap renewable power — into stored high-temperature heat for steam, hot air or power.
Project & partnership desk
Planning Phase Change Materials?
Tell us your heat demand, site and timeline — BARREL engineers, suppliers and partners will help you scope it.